From Full stopping to transparency in a holographic model of heavy ion collisions

We numerically simulate planar shock wave collisions in anti-de Sitter space as a model for heavy ion collisions of large nuclei. We uncover a crossover between two different dynamical regimes as a function of the collision energy. At low energies the shocks first stop and then explode in a manner approximately described by hydrodynamics, in close similarity with the Landau model. At high energies the receding fragments move outwards at the speed of light, with a region of negative energy density and negative longitudinal pressure trailing behind them. The rapidity distribution of the energy density at late times around midrapidity is not approximately boost invariant but Gaussian, albeit with a width that increases with the collision energy.

Mano a mano con David Roas

El escritor David Roas acaba de publicar su novela La estrategia del koala (Barcelona, Candaya, 2013, 234 pp.). Le pedimos que nos desvele alguno de sus entresijos, y la novela se vuelve aún más sugerente. En alguna de sus respuestas nos parece seguir escuchando a su personaje Marcos Fontana

La (De)construcció de la masculinitat en el teatre de David Mamet

La reflexió efectuada per la teoria contemporania sobre la representació del genere es materialitza d'una manera privilegiada en el teatre. Esta clar que la perforrnativitat intrinseca del fenomen teatral és un espai idoni per qüestionar la construcció de la representació generica. No hi ha dubte que I'especificitat comunicativa del teatre es troba en la «fisicalitat)): I'element corporal té una importancia clau, ja síguí per la presencia física de I'equip actoral i del públic i per la condició efímera (el fet que cap representació no és igual a cap altra). Judith Butler ha escrit sobre el fet que els actes que constitueixen el genere tenen un paral.lelisrne en les actes performatius dels contextos teatrals. La identitat de genere no és una identitat completa, sinó que és una identitat que es construeix, una realització performativa en la qual creiern, i que representem corn si fos una creenca, com si fos una qüestió de fe. Per tant, les possibilitats de transformació del genere es troben en la relació arbitraria d'aquests actes i en la possibilitat d'un altre tipus de repetició (Butler, 1990: 33). L'obra del dramaturg, director, guionista i assagista nord-america David Marnet pot considerar-se una reflexió sobre la construcció de la masculinitat i, de retruc, de les tensions i reptes a que la masculinitat es troba sotmesa en el tornbant de segle. 1. ES

Mir-21-Sox2 Axis Delineates Glioblastoma Subtypes with Prognostic Impact.

UNLABELLED: Glioblastoma (GBM) is the most aggressive human brain tumor. Although several molecular subtypes of GBM are recognized, a robust molecular prognostic marker has yet to be identified. Here, we report that the stemness regulator Sox2 is a new, clinically important target of microRNA-21 (miR-21) in GBM, with implications for prognosis. Using the MiR-21-Sox2 regulatory axis, approximately half of all GBM tumors present in the Cancer Genome Atlas (TCGA) and in-house patient databases can be mathematically classified into high miR-21/low Sox2 (Class A) or low miR-21/high Sox2 (Class B) subtypes. This classification reflects phenotypically and molecularly distinct characteristics and is not captured by existing classifications. Supporting the distinct nature of the subtypes, gene set enrichment analysis of the TCGA dataset predicted that Class A and Class B tumors were significantly involved in immune/inflammatory response and in chromosome organization and nervous system development, respectively. Patients with Class B tumors had longer overall survival than those with Class A tumors. Analysis of both databases indicated that the Class A/Class B classification is a better predictor of patient survival than currently used parameters. Further, manipulation of MiR-21-Sox2 levels in orthotopic mouse models supported the longer survival of the Class B subtype. The MiR-21-Sox2 association was also found in mouse neural stem cells and in the mouse brain at different developmental stages, suggesting a role in normal development. Therefore, this mechanism-based classification suggests the presence of two distinct populations of GBM patients with distinguishable phenotypic characteristics and clinical outcomes. SIGNIFICANCE STATEMENT: Molecular profiling-based classification of glioblastoma (GBM) into four subtypes has substantially increased our understanding of the biology of the disease and has pointed to the heterogeneous nature of GBM. However, this classification is not mechanism based and its prognostic value is limited. Here, we identify a new mechanism in GBM (the miR-21-Sox2 axis) that can classify ∼50% of patients into two subtypes with distinct molecular, radiological, and pathological characteristics. Importantly, this classification can predict patient survival better than the currently used parameters. Further, analysis of the miR-21-Sox2 relationship in mouse neural stem cells and in the mouse brain at different developmental stages indicates that miR-21 and Sox2 are predominantly expressed in mutually exclusive patterns, suggesting a role in normal neural development.

Oxidative stress in gastric mucosa of asymptomatic humans infected with Helicobacter pylori: effect of bacterial eradication.

BACKGROUND: Inducible nitric oxide synthase (iNOS) and interleukin 8 (IL-8) are positive in approximately 50% of Helicobacter pylori-related diseases but it is not clear whether oxidative stress is also present in H. pylori asymptomatic humans. Our aim was to study the expression of iNOS, superoxide dismutase, catalase and IL-8 production in H. pylori-infected asymptomatic humans, and to investigate the effect of eradication of H. pylori. MATERIALS AND METHODS: Biopsies of corpus and antrum of asymptomatic H. pylori positive and negative humans served for determination of the gastritis score and H. pylori status; iNOS was measured by reverse transcriptase polymerase chain reaction and immunohistochemistry and superoxide dismutase and catalase by immunohistochemistry. IL-8 in biopsies was assessed by enzyme-linked immunosorbent assay. RESULTS: Immunostaining of iNOS, catalase and superoxide dismutase was significantly associated with H. pylori infection and was localized to inflammatory cells. IL-8 concentrations were greater in the H. pylori positive than H. pylori negative group and decreased after bacterial eradication. A decrease in staining for iNOS and catalase was observed after H. pylori eradication. CONCLUSIONS: INOS and antioxidant enzymes are present in gastric biopsies of asymptomatic H. pylori positive humans. Eradication caused a significant decrease in staining for iNOS and catalase. These results indicate that oxidative stress occurs in asymptomatic patients and can be modulated by H. pylori eradication.

Adaptació cinematogràfica de la novel·la Cuatro amigos de David Trueba

Aquest treball és una adaptació d'una obra literària a guió cinematogràfic d'un llargmetratge.

La llengua de l’heroi : notes sobre la llengua del segle xx a partir de les traduccions catalanes de David Copperfield de Charles Dickens

A comparative study of the two published Catalan translations of Charles Dickens’ David Copperfield, the first translated by Josep Carner in 1930 but not published until 1964, and the second by Joan Sellent in 2003. The analysis shows that both translations, magnificent, reflect the unique evolution of the language model that the translators pass on to their readers, an evolution shaped by the complex history of the Catalan language in the 20th century, which is still to be written